Regulator for dynamo-electric machines



(No Model.)

R. H. MATHER.

REGULATOR FOR DYNAMO ELEGTRIG MACHINES.

No 337,778. Patented Mar. 9, 1886.

UNITE STATES PATENT OFFICE.

RICHARD H. MATHER, OF VINDSOR, CONNECTICUT.

REGULATOR FOR DYNAMO-ELECTRIC MACHINES.

SPECIFICATION forming part of Letters Patent No. 337,778, dated March 9,1886.

Application filed May 21, 1884. Serial No. i322. (No model.)

of Connecticut, have invented certain new and useful Improvements inRegulators for Dynamo-Electric Machines, of which the following is afull, clear, and exact description, whereby a person skilled in the artto which it appertains can make and use the same, reference being had tothe accompanying drawings.

My invention is an automatic regulator for dynamo-electric machines. Thelatter term is here used in a broad sense, including all machines forconverting energy in the form of dynamical power into energy in the formof electric currents by the operation of causing conductorsusually inthe form of copper wire-to rotate in a magncticfield.

The object of my invention is so to regulate a dynamo-electric machinethat the same shall produce a standard or uniform electro-motive forceor current, as the case may be, regardless of variations of resistancein the external circuit, a result which is particularly desirable inelectric lighting and in the electric deposition of metals. My devicefor accomplishing this object is a variable magnetic switch or shuntconsisting of an electromagnetic armature of the field-magnet, and mayfor convenience be termed a detractor.

I proceed to point out the best mode of applying my invention todifferent types of dynamos.

In the drawings, Figure l is a diagrammatic representation of myinvention as applied to a shunt-dynamo with the detractor in the maincircuit. Fig. 2 is a diagrammatic representation of my invention asapplied to a series dynamo, with detractor in a special shunt-circuit.

In these drawings, F is the field-magnet,

. whose particular form is unimportant in this connection. The north andthe south poles of the field-magnet, which are lettered, respectively, Nand S, should, however, be of convenient form for the juxtaposition ofthe detractor, as hereinafter described.

A is the revolving armature, provided with brushes and commutator in theusual manner, as shown.

Dis the detractor, which is a core of soft iron wound as anelectromagnet and having north and south poles or pole-pieces lettered,respectively, N and S, and of any convenient form for contact with N andS, before mentioned, as shown.

The fieldmagnet and detractor are fixed with their like poles together,as shown, and may conveniently be bolted together.

The amount of winding of the detractor should be such as to produce thesame intensity of magnetization therein as exists in the fieldmagnet.

In order that both the magnetic conductivity of the detractor, asdependent upon the quantity of iron utilized therein as a shunt, and theelectromagnetic power of the detractor-helix, as dependent. upon thequantity of wire composing the same, may be properly proportionedrelatively to each other in the case of a machine whichis to beregulated for constant electro-motive force, (see Fig. 1,) I proceed inthe construction of such machine in the following manner: Havingcompleted the machine in the usual manner as to all parts thereof,except the detractor, I ascertain by experiment what quantity of wire ofthe size which is selected for the purpose is neces sary to produce inthe detractor, when wound thereon and placed in circuit, the sameintensity of magnetization as is produced in the field magnet by thefield -inagnet coil in the normal operation of the machine. The size ofthe wire which is selected for this purpose should be as large asconvenient in order that the same may not reduce the efiiciency of themachine by unnecessarily increasing the resistance of the circuit. NextI introduce the wire so selected and determined into the circuit whichcontains the lamps or other resistances representing the work to bedone. Then, having placed in circuit the maximum number of lamps whichthe machine is designed to operate, I run the machine at such speed aswill bring all the lamps to the desired degree of brilliancy. This isthe normal speed of the machine. Next, before winding the detractor, Iplace the same unwound in its position of contact with the field-magnet,as shown in the drawings, and as described above. At the same time, andwhile the wire before selected remains in circuit, I turn out all thelights in the circuit except one, and observe the result. If the singleremaining light is L99 bright, I increase the mass of the detractor,

and if too dim I remove some of the iron from the core of the detractoruntil a brilliancy slightly below the standard brilliancy is obtained.The next step is to wind the wire so selected and ascertained onto thecore of the detractor, so made of the proper size, in the manner alreadydescribed. This process renders the mass and winding of the detractorpractically correct both for the maximum and for the'minimum number oflights in circuit, and no special adjustment further than this isnecessary in order that the machine may operate satisfactorily with anyintermediate numberof lights in circuit.

In the construction of the dynamo regulated for constant current, Fig.2, I adopt a similar method for determining the size and winding of thedetractor.

The remaining features of construction and the appropriate connectionswill sufficiently appear from thedrawings and from the mode ofoperation, as hereinafter explained.

The work to be done may be taken to be electric lighting by lamps in themain circuit.

The mode of operation in the case of the shunt-dynamo having thedetractor in the main circuit, Fig. 1, is as follows: The machine beingadjusted to operate the maximum numher of incandescent lamps in a propermanner, if a number of these lamps less than all of them be turned out,then although the current in the main circuit is thereby diminished, yetthe electro-motive force of the machine is increased. This increase ofelectro motive force increases the energy of the field-magnet, so thatthe intensity of its field tends to increase too much; but thediminution of the current in the main circuit, by diminishing theelectro-magnetic power of the helix of the detractor, causes the latterto be less magnetized than before, so that less resistance is offered tothe passage of magnetism through the detractor from pole to pole of thefield-magnet; hence an increasing quantity of magnetism is shunted awayfrom the armature A and through the detractor, so that the field ofmagnet F tends to be weakened by the loss of the magnetism so shuntedthrough the detractor at the same time that the said field tends to anundue increase of intensity from the increase of electro motive force,'as just described, whereby an equilibrium of effects is produced,

and a uniform electro-motive force is pre-' served regardless of theextinction of lights,

as stated, and the remaining lights in the circuit continue to burnwithout increase of briln the case of the series dynamo having thedetractor in a special shunt-circuit, as shown This increase ofcurrentincreases the strength of the field-magnet, which in turn againincreases the current, so that its field would be too intense for thelights in circuit; but the diminished current in the shunt-circuitresulting from the diminution of resistance just mentioned causes adiminution of the magnetic power'of the helix of the detractor.

The latter being in consequence less magnetized than before, allows morethan before of the magnetism of the field magnet to be shunted throughthe detractor, so that by this magnetic shunt the field of the magnet Ftends to be weakened at the same time that the field tends, as beforeexplained, to become too intense through undue increase of current;hence an equilibrium of effects is produced, and a'uniform current ispreserved regardless of extinction of resistance in the main circuit inthe manner supposed, and the remaining are lights continue to burnwithout increase of brilliancy.

The application of my invention in the case of a separately-exciteddynamo and in the case of a magneto-dynamo or magneto-electriogenerator, as it is called, as well as in the case of mixed types ofdynamos needs no separate illustration or explanation, beingsufficiently obvious from the applications already illustrated andexplained. The general plan isthis: Across thepoles of thefield-magnet Iplace a magnetic shunt which is the core of an electro-magnet ofvariable magnetic resistance, which resistance is automaticallycontrolled and adjusted by the action of the coils of suchelectro-magnet. The detractor maintains a constant electro-motive forceif its coils be in the main circuit. It maintains a constant current ifits coils be in a shuntcircuit.

It is to be observed that this invention is a governor to preserveuniformity of current or electro-motive force as against variations inthe number of lights in operation or as against other variableresistance in the external circuit, but is not a governor as againstirregularity or variations in the speed of the engine or dynamo.

So far as concerns the present case, I disclaim all things which areclaimed in Letters Patent of the United States No. 334,712,

iron bridges placed directly across said poles.

and inclosing the armature, thereby magneticall'y short-circuiting thefield of force, said bridges being provided with proper helices, asdesired, and independent of the field-magnet coils; but

I claim as my invention, and desire to se- I cure by Letters Patent--7 1. Ina dynamo-electric machine, the field- 'magnet F, in combinationwith the detractor D, said magnet and detractor having constantly-closedcircuit-connections and being placed one in the main or working-circuitof such machine, and the other in a derived circuit about the work,substantially as and for the purpose specified.

2. In a dynamo-electric machine, a fieldmagnet, in combination with afixed armature thereof, said field-magnet and armature being severallywound as electro-magnets and constantly connected, one in theworking-circuit of such machine and the other in a shunt-circuit aboutthe work, substantially in the manner and for the purpose specified.

3. In a dynamo-electric machine, a fieldmagnet, in combination with amagnetic switch or shunt between the poles thereof, said fieldmagnet andswitch being electro magnets which are constantly connected in parallelarc, substantially in the manner and for the purpose specified.

4. In a dynamo-electric machine, an electromagnet whose core is amagnetic shunt between the poles of the field-magnet, and whose helix,being in a constantly-closed circuit, is 2 5 connected in parallel withthe helix of such field-magnet, substantially in the manner and for thepurpose specified.

5. In adynamo-electric machine, an electromagnet whose poles arerespectively adjacentgo field-magnet, substantially in the manner and cfor the purpose specified.

In witness whereof I have hereunto set my name in the presence of twosubscribing witnesses.

RICHARD H. MATHER.

'W itn esses:

WILLARD EDDY, RALPH H. PARK.

